Making Sense of Trout

When you're noisy and you smell bad, fish don't like you.

Field & Stream Online Editors

On the day I bought my first small rowing boat, I eagerly attacked the nearest lake like a trout attacks a mayfly. Every time I swept the oars they let out a sound like a startled goose. At the time, I didn't relate that awful noise to my total lack of luck.

A fellow in a nearby boat was rowing and trolling a fly in similar fashion, but was catching trout after trout. Seeing his results prodded me into ever more frantic rowing. Finally he read my distress signals, rowed over, and laid a hand on my gunwale. "What fly are you using?" he asked, quietly.

I held up a big, bright streamer. He handed me a wet fly so small and drab I was certain no trout would ever notice it. "This is what I've been using," he said. "Tie it on and try it."

While I fumbled to tie his fly to my tippet, he pulled out a can of WD-40, lifted my near oar, and shot a squirt into the oarlock socket. He leaned across the boat and did the same to the far oarlock. He then shoved away, wishing me luck.

I thanked him and rowed off-now in virtual silence-and almost instantly hooked a trout. I owned no net, so I hoisted the flapping fish over the side, afraid it might get off. It didn't, though I did lose a few of those that followed. But I was by then such a sudden expert that losing an occasional trout did not bother me at all.

Trout Senses
Trout possess a set of senses that protect them from predators, including anglers. If you ignore those senses, trout will be warned of your approach. If you honor those senses, you'll be able to get within easy casting range-or in my youthful case, into rowing range-and have far less trouble catching them.

The sense I'd failed to honor that day on the lake was hearing, but it's not the same we have with our ears. Air is not dense enough to transfer sound waves into water. You can shout to your friends, curse your luck, or make any noise you like in the air without bothering the fish.

But a trout's lateral line picks up low-frequency vibrations generated by anything in contact with water. That means you shouldn't row with squeaky oars or thump the bottom of the boat. Those warnings get transmitted right to the trout. When you wade a stream, move slowly. Don't knock rocks together. Avoid grinding the bottom gravel. When you stalk banks, whether the water is moving or still, tread lightly or you'll send the trout sailing.

Vision is the most highly developed sense in trout. They locate almost all of their prey by sight. They're also alerted to predators by the same sense. Kingfishers, ospreys, and herons all attack trout from above. At the least sight of anything moving over their heads, most trout dart for cover.

When fly casting, don't make false casts directly over trout. Always make them off to one side. Then angle your delivery stroke up and across the current, not straight upstream and directly over visible trout or their likely lies.

**Getting Closer **
If you stand tall and suddenly move in so close to a trout that you loom into its view, it's gone. How close is too close? The angle of light refraction off the surface dictates a simple formula for how low you must be to stay beneath a trout's line of sight. At 40 feet, unless you play for the NBA, you can stand upright and the trout's line of sight will pass over your head. At 30 feet, you need to bend over. At 20 feet, you'd best be on your knees. At 10 feet, you'll either be crawling or else eyeball-to-eyeball with a trout you have little chance to catch.

But "suddenly" is the key to that entire formula. If you insert yourself slowly into a trout's line of sight, at any distance, it's more likely to perceive you as a tree than a threat. You can cast, right there in full view, if you don't whip your rod back and forth. If you move it as slowly and gracefully as a gentle wind might wave a willow, trout might go on feedinng no matter how close you get.

Strangely, the sight of your wader-clad legs approaching trout underwater doesn't bother them if you move slowly and bang no rocks. Careful wading and placing part of your height underwater rather than sticking up above it is an excellent way to flyfish beneath a trout's visual radar.

** Smelling Trouble**
Trout can smell trouble coming. Their nostrils, located on their snouts just in front of their eyes, are so sensitive they can detect molecules diluted by water to scant parts per million. I always dismissed this sense, until an incident while floating my home river, Oregon's broad and brawling Deschutes, convinced me to honor it as much as any other.

It was a hot summer day, and I was wading wet. I'd just lathered my legs with sunscreen when I noticed a line of trout sipping mayfly duns along the edge of a lazy eddy.

I drifted past the eddy before nosing the boat to shore, upcurrent from the rising trout. I tied on a size 16 Comparadun-style Pale Morning Dun dry, slipped over the side of the boat, and moved into position to present the fly with downstream wiggle casts. As I approached the nearest rises, they winked out like lights.

I waded a few feet farther downcurrent and into position to reach the next set of rises. As I approached, they winked off as well. I waded slowly, sending no ripples or waves before me, the full length of that eddy. Rises continued to blink out in front of me as I went until all activity had stopped. I never launched a cast. It finally occurred to me that the sunscreen scent on my legs was wafting along ahead of me in the gentle current.

I'd failed to honor one of the senses of the trout, thus warning them of my approach. That taught me to keep my waders clean, and to wade upstream, not down, whenever I wade wet. A trout's sense of smell is more acute than we think. To them, we stink.

Trout never fail to appreciate the sound, sight, or smell of an approaching angler. If you fail to honor any of those critical senses, you'll frighten more fish than you catch. If you do right by them, however, you'll find it easy to slip up on trout.